If there are no older chickens in the coop, introducing the babies to their new home will be a walk in the park.
Just move them in, hang out with them for a bit while they explore the new digs, then leave them inside for at least two days with food and water. Check on them frequently so they know you haven't abandoned them. Two days should be plenty of time to get them used to the coop as safety and home. Then on the morning of the third day, open the pop hole and coax them out through it. In the evening you may need to teach them how to go inside. This usually involves picking up a couple of the chicks and pushing them through the doorway. A lot of times the rest will hear their mates inside and will hop in to join them.
With some chicks, you may need to help them go in for several nights before they get the idea. Just don't wait until it's too dark for them to see. If they can't see well to go inside, panic can ensue. They have a very strong instinct to go inside at dark time. They'll catch on very quickly.
